Either would work just fine! I have both calibers. I have always been partial to a 30 caliber hole in an animal though, my thinking is a little better blood trail possibly but haven't had any proof of this notion? Something about a modern 7x57 makes me go "heee heee"!
I ended up getting a 7mm-08 as my primary hunting rifle but will never be without a .30 caliber in the rack.
